Anatomy Thorax Abdomen · Year 1 · from Anatomy Thorax Abdomen
Case 2: Aortic Stenosis
Clinical Presentation
A 72-year-old male presents with progressive exertional dyspnea and two syncopal episodes over the past month. He has a history of hypertension and was told he had a heart murmur years ago. He now becomes short of breath walking one block and experiences chest tightness with exertion. On examination, blood pressure is 130/85 mmHg with a narrow pulse pressure. Carotid pulses are diminished with a slow upstroke (pulsus parvus et tardus).
Cardiac auscultation reveals a harsh crescendo-decrescendo systolic ejection murmur grade 4/6 best heard at the right second intercostal space (aortic area), radiating to the carotid arteries. S2 is diminished due to calcification limiting leaflet mobility. A systolic thrill is palpable at the right upper sternal border. Echocardiography shows a heavily calcified, trileaflet aortic valve with a valve area of 0.7 cm2 (normal >3 cm2) and a mean gradient of 52 mmHg, consistent with severe aortic stenosis. The left ventricle is concentrically hypertrophied. The patient undergoes transcatheter aortic valve replacement (TAVR) with significant symptomatic improvement.
Key Anatomical Points
- The aortic valve has three semilunar cusps: right coronary, left coronary, and non-coronary (posterior)
- Each cusp has a nodule at its center and lunulae on either side that overlap during closure
- The coronary arteries arise from the aortic sinuses (of Valsalva) just above the right and left coronary cusps
- Progressive calcification restricts cusp mobility, causing outflow obstruction
Key Learning Points
- The aortic valve is anatomically positioned at the right third intercostal space but is best auscultated at the right second intercostal space where blood flow carries the sound
- Aortic stenosis causes the classic triad of angina, syncope, and heart failure
- Left ventricular hypertrophy develops to overcome the increased afterload
- The aortic valve lies in intimate relation to the membranous septum and the bundle of His, which can be injured during valve replacement